scholarly journals Evaluation of the Murine Immune Response to Xenopsylla cheopis Flea Saliva and Its Effect on Transmission of Yersinia pestis

2014 ◽  
Vol 8 (9) ◽  
pp. e3196 ◽  
Author(s):  
Christopher F. Bosio ◽  
Austin K. Viall ◽  
Clayton O. Jarrett ◽  
Donald Gardner ◽  
Michael P. Rood ◽  
...  
Vaccine ◽  
2010 ◽  
Vol 28 (36) ◽  
pp. 5810-5816 ◽  
Author(s):  
Ascención Torres-Escobar ◽  
María Dolores Juárez-Rodríguez ◽  
Christine G. Branger ◽  
Roy Curtiss

2007 ◽  
Vol 44 (4) ◽  
pp. 678-682 ◽  
Author(s):  
Rebecca J. Eisen ◽  
Aryn P. Wilder ◽  
Scott W. Bearden ◽  
John A. Montenieri ◽  
Kenneth L. Gage

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Voahangy Andrianaivoarimanana ◽  
Alice Lantoniaina Iharisoa ◽  
Lila Rahalison ◽  
Marie Laurette Ralimanantsoa ◽  
Maherisoa Ratsitorahina ◽  
...  

Abstract Background Plague, a fatal disease caused by the bacillus, Yersinia pestis, still affects resources-limited countries. Information on antibody response to plague infection in human is scarce. Anti-F1 Ig G are among the known protective antibodies against Y. pestis infection. As a vaccine preventable disease, knowledge on antibody response is valuable for the development of an effective vaccine to reduce infection rate among exposed population in plague-endemic regions. In this study, we aim to describe short and long-term humoral immune responses against Y. pestis in plague-confirmed patients from Madagascar, the most affected country in the world. Methods Bubonic (BP) and pneumonic plague (PP) patients were recruited from plague- endemic foci in the central highlands of Madagascar between 2005 and 2017. For short-term follow-up, 6 suspected patients were enrolled and prospectively investigated for kinetics of the anti-F1 IgG response, whereas the persistence of antibodies was retrospectively studied in 71 confirmed convalescent patients, using an ELISA which was validated for the detection of plague in human blood samples in Madagascar. Results Similarly to previous findings, anti-F1 IgG rose quickly during the first week after disease onset and increased up to day 30. In the long-term study, 56% of confirmed cases remained seropositive, amongst which 60 and 40% could be considered as high- and low-antibody responders, respectively. Antibodies persisted for several years and up to 14.8 years for one individual. Antibody titers decreased over time but there was no correlation between titer and time elapsed between the disease onset and serum sampling. In addition, the seroprevalence rate was not significantly different between gender (P = 0.65) nor age (P = 0.096). Conclusion Our study highlighted that the circulating antibody response to F1 antigen, which is specific to Y. pestis, may be attributable to individual immune responsiveness. The finding that a circulating anti-F1 antibody titer could persist for more than a decade in both BP and PP recovered patients, suggests its probable involvement in patients’ protection. However, complementary studies including analyses of the cellular immune response to Y. pestis are required for the better understanding of long-lasting protection and development of a potential vaccine against plague.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Tiandi Wei ◽  
Jing Gong ◽  
Guojing Qu ◽  
Mingyu Wang ◽  
Hai Xu

Abstract Background Yersinia pestis, the etiological pathogen of plague, is capable of repressing the immune response of white blood cells to evade phagocytosis. The V-antigen (LcrV) was found to be involved in this process by binding to human Toll-like Receptor 2 (TLR2). The detailed mechanism behind this LcrV and TLR2 mediated immune response repression, however, is yet to be fully elucidated due to the lack of structural information. Results In this work, with protein structure modelling, we were able to construct a structure model of the heterotetramer of Y. pestis LcrV and human TLR2. Molecular dynamics simulation suggests the stability of this structure in aquatic environment. The LcrV model has a dumbbell-like structure with two globule domains (G1 at N-terminus and G2 away from membrane) connected with a coiled-coil linker (CCL) domain. The two horseshoe-shape TLR2 subunits form a V-shape structure, are not in direct contact with each other, and are held together by the LcrV homodimer. In this structure model, both the G1 and CCL domains are involved in the formation of LcrV homodimer, while all three domains are involved in LcrV-TLR2 binding. A mechanistic model was proposed based on this heterotetrameric structure model: The LcrV homodimer separates the TLR2 subunits to inhibit the dimerization of TLR2 and subsequent signal transfer for immune response; while LcrV could also inhibit the formation of heterodimers of TLR2 with other TLRs, and leads to immune response repression. Conclusions A heterotetrameric structure of Y. pestis LcrV and human TLR2 was modelled in this work. Analysis of this modelled structure showed its stability in aquatic environments and the role of LcrV domains and residues in protein-protein interaction. A mechanistic model for the role of LcrV in Y. pestis pathogenesis is raised based on this heterotetrameric structure model. This work provides a hypothesis of LcrV function, with which further experimental validation may elucidate the role of LcrV in human immune response repression.


2020 ◽  
Vol 57 (6) ◽  
pp. 1997-2001
Author(s):  
Athena Lemon ◽  
Nathan Cherzan ◽  
Viveka Vadyvaloo

Abstract Plague, caused by the flea-transmitted bacterial pathogen Yersinia pestis, is primarily a disease of wild rodents distributed in temperate and tropical zones worldwide. The ability of Y. pestis to develop a biofilm blockage that obstructs the flea foregut proventriculus facilitates its efficient transmission through regurgitation into the host bite site during flea blood sucking. While it is known that temperature influences transmission, it is not well-known if blockage dynamics are similarly in accord with temperature. Here, we determine the influence of the biologically relevant temperatures, 10 and 21°C, on blockage development in flea species, Xenopsylla cheopis (Rothschild) and Oropsylla montana (Baker), respectively, characterized by geographical distribution as cosmopolitan, tropical or endemic, temperate. We find that both species exhibit delayed development of blockage at 10°C. In Y. pestis infected X. cheopis, this is accompanied by significantly lower survival rates and slightly decreased blockage rates, even though these fleas maintain similar rates of persistent infection as at 21°C. Conversely, irrespective of infection status, O. montana withstand 21 and 10°C similarly well and show significant infection rate increases and slightly greater blocking rates at 10 versus 21°C, emphasizing that cooler temperatures are favorable for Y. pestis transmission from this species. These findings assert that temperature is a relevant parameter to consider in assessing flea transmission efficiency in distinct flea species residing in diverse geographical regions that host endemic plague foci. This is important to predict behavioral dynamics of plague regarding epizootic outbreaks and enzootic maintenance and improve timeous implementation of flea control programs.


2014 ◽  
Vol 8 (12) ◽  
pp. e3322 ◽  
Author(s):  
Lalit Batra ◽  
Shailendra K. Verma ◽  
Durgesh P. Nagar ◽  
Nandita Saxena ◽  
Prachi Pathak ◽  
...  

Author(s):  
Paula Alexandra Oliveira ◽  
Ana Faustino Ana Faustino

ResumoO rato está na base de importantes descobertas na área da medicina. Contudo, nem sempre foi bem visto pela sociedade. No século XIV abateu-se sobre a Europa uma pandemia, a Peste Negra, causada por uma bactéria (Yersinia pestis) transmitida ao Homem por uma pulga (Xenopsylla cheopis), cujo hospedeiro era o rato (Rattus rattus). Esta doença vitimou aproximadamente 150 milhões de pessoas. Estava-se longe de imaginar o contributo que o rato viria a ter na saúde humana.No século XVII o rato proliferou descontroladamente, surgindo uma nova profissão: os caçadores de ratos. Estes indivíduos ganhavam dinheiro com a captura e venda destes animais para alimentação. Nessa época apareceu um desporto novo e as apostas a ele associadas: as lutas de ratos. Como resultado desse desporto, aumentaram os acasalamentos consanguíneos e surgiram variações na pelagem do rato, aparecendo os primeiros ratos albinos. Em 1828 foram utilizados os primeiros ratos albinos num ensaio experimental sobre o estudo do efeito do jejum. Mais tarde, em 1906, no Instituto Wistar, Helen Dean King desenvolveu uma estirpe a partir dos ratos albinos, designada de Wistar, para uso na investigação biomédica.Ainda no século XX o uso do rato de laboratório alargou-se a estudos de aprendizagem em labirinto, nutrição, reprodução, genética e cancro, e consequentemente mais estirpes de animais foram desenvolvidas, passando a existir empresas com o propósito de os vender para investigação. A importância desta espécie pode comprovar-se pela análise do número de artigos publicados anualmente com recurso à sua utilização. Neste trabalho apresenta-se uma revisão histórica do uso do rato na investigação, evidenciando-se as caraterísticas que fizeram deste animal um modelo único na pesquisa biomédica. Palavras-chave: Investigação, Peste Negra, Rattus rattus, Wistar Abstract The rat is the basis of important findings in Medicine. However, it was not always well-seen by the society. In the 14th century, the Europe was affected by a pandemic disease, Black Pestis, caused by a bacterium (Yersinia pestis) transmitted to the Man by a flea (Xenopsylla cheopis), whose host was the rat (Rattus rattus). This disease victimized approximately 150 million people. It was far from imaging the contribution that the rat would have for human health. In the 17th century, the rat proliferated wildly, emerging a new job: the rat hunters. These people earnt money with the capture and selling of these animals for food. At that time appeared a new sport and the bets associated to it: the rat fights. Because of this new hobby, the consanguineous mating increased and appeared variations on rat coat, appearing the first albino rats. In 1828 the albino rats were used by the first time in an experimental assay about the fasting effects. Later, in 1906, in the Wistar Institute, Helen Dean King developed a strain from albino rats, called Wistar, for use in biomedical research. Still in the 20th century, the use of laboratory rats was expanded to studies of learning, nutrition, reproduction, genetics and cancer, and consequently more strains were developed by companies with the purpose to sell them for research. The importance of this specie may be evidenced by the analysis of the number of scientific works published annually using it. In this work, a historical review of the use of the rat in the investigation is provided, evidencing the characteristics that made it a unique model in biomedical research. Keywords: Black Pestis, Investigation, Rattus rattus, Wistar


2021 ◽  
Vol 12 ◽  
Author(s):  
Sergei Biryukov ◽  
Jennifer L. Dankmeyer ◽  
Zain Shamsuddin ◽  
Ivan Velez ◽  
Nathaniel O. Rill ◽  
...  

Relatively recent advances in plague vaccinology have produced the recombinant fusion protein F1-V plague vaccine. This vaccine has been shown to readily protect mice from both bubonic and pneumonic plague. The protection afforded by this vaccine is solely based upon the immune response elicited by the F1 or V epitopes expressed on the F1-V fusion protein. Accordingly, questions remain surrounding its efficacy against infection with non-encapsulated (F1-negative) strains. In an attempt to further optimize the F1-V elicited immune response and address efficacy concerns, we examined the inclusion of multiple toll-like receptor agonists into vaccine regimens. We examined the resulting immune responses and also any protection afforded to mice that were exposed to aerosolized Yersinia pestis. Our data demonstrate that it is possible to further augment the F1-V vaccine strategy in order to optimize and augment vaccine efficacy.


1999 ◽  
Vol 67 (4) ◽  
pp. 1922-1928 ◽  
Author(s):  
Gretchen E. Benner ◽  
Gerard P. Andrews ◽  
W. Russell Byrne ◽  
Susan D. Strachan ◽  
Allen K. Sample ◽  
...  

ABSTRACT There is limited information concerning the nature and extent of the immune response to the virulence determinants ofYersinia pestis during the course of plague infection. In this study, we evaluated the humoral immune response of mice that survived lethal Y. pestis aerosol challenge after antibiotic treatment. Such a model may replicate the clinical situation in humans and indicate which virulence determinants are expressed in vivo. Immunoglobulin G enzyme-linked immunosorbent assay and immunoblotting were performed by using purified, recombinant antigens including F1, V antigen, YpkA, YopH, YopM, YopB, YopD, YopN, YopE, YopK, plasminogen activator protease (Pla), and pH 6 antigen as well as purified lipopolysaccharide. The major antigens recognized by murine convalescent sera were F1, V antigen, YopH, YopM, YopD, and Pla. Early treatment with antibiotics tended to reduce the immune response and differences between antibiotic treatment regimens were noted. These results may indicate that only some virulence factors are expressed and/or immunogenic during infection. This information may prove useful for selecting potential vaccine candidates and for developing improved serologic diagnostic assays.


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